SANAA (Reuters) - Tribesmen blew up impoverished Yemen's main oil export pipeline on Thursday, halting the flow of its main source of foreign currency, security and oil officials said.

The Arabian Peninsula state, which relies on crude exports to finance up to 70 percent of budget spending, has suffered frequent bombings of its main pipeline in the central Maarib province since an uprising broke out in 2011.

"The attack has stopped the flow of exports, but we have engineering teams fixing the damage now and we expect that it will be repaired by tomorrow," said an oil ministry official.

(Editing by Kevin Liffey)